In 1962, James West and Gerhard Sessler patented a small, low-cost microphone; their design is now inside 90% of the 2 billion microphones made each year

Every call you've ever made via FaceTime, every recording you've ever saved as a voice memo, every muffled conversation over Zoom, every TikTok voiceover: odds are, the audio is funneled through some sort of piece of technology that most people have never even heard of, and which was the result of an early lab mishap in 1962. According to a 1962 original research paper titled “Self‐Biased Condenser Microphone with High Capacitance,” published in The Journal of the Acoustical Society of America, Bell Labs scientists Gerhard Sessler and James West described a "new kind of condenser microphone with solid dielectric between the electrodes," a device which didn't require a large power source to operate. This paper, brief and unimpressive-sounding as it may seem, would come to define the microphone technology utilized by almost everyone today.

A faulty headphone, and a happy accident

West had joined Bell Laboratories in New Jersey after his college internship, and in the early 60's, he worked alongside Sessler, a German physicist, to develop a more reliable hearing-aid-style earphone. Condensers of previous years worked well enough, but they were large, delicate, and expensive devices that required a heavy battery to power a current between two plates.

The breakthrough, oddly enough, came from an accidental mishap while testing out their design. Sessler and West had reversed the polarity of a battery and shorted it out, and in their exploration of the incident, found a material which could hold enough of an electrical charge to power such a device without the need for a battery at all. This particular substance had, coincidentally, been released on the market just prior to their discovery: Teflon.

Why Teflon changed everything

Why Teflon, specifically, is yet to be fully discovered, but it has been shown to be able to hold a charge for several decades, and in some cases, even up to a century-long period of time. When sandwiched between two electrodes, the thin charged layer of Teflon forms a microphone that is affordable, small, durable, and does not need the bulky power source that was required by previous condenser microphones.

The patent was applied for by Sessler and West in May 1962 and was approved in January 1964. By 1968, the "foil electret microphone" was being produced. The timing couldn't have been better. This was the time when consumer electronics started getting smaller: the transistor radio, the cassette recorder, and later on, the telephone, all required parts that were small and affordable. The electret microphone was just the right fit.

A common piece of technology, making things easier

According to a 2023 American Physical Society (APS) article, electret microphones were used in telephones and other consumer products almost immediately after the patent filing, and eventually became a staple of many industries. Today, the same design is seen in laptop voice recorders, baby monitors, hearing aids, and even in the headphones that you may have been listening to as you read this.

An interesting observation to make here is that James West, a young Black man growing up in segregated Virginia, who would go on to become one of the few Black research scientists at Bell Labs, has more than 250 patents to his name across the span of his 40-year career, and was inducted into the National Inventors Hall of Fame with Sessler in 1999. West would later go on to teach at Johns Hopkins University as a professor. Both the founding fathers of this particular piece of technology received the Franklin Institute's Benjamin Franklin Medal in 2010 for their work on the microphone.

A strange sort of legacy

It's rare to say the least that almost any given piece of technology that involves a voice being recorded or played back in some form has used this particular type of device. Nine out of every ten microphones produced today are either the result of, or are related to this one discovery. And yet, for all of its far-reaching effects, most people would not even have heard of the two names behind it. For the youngsters who utilise voice recording in their day-to-day lives, it's oddly nostalgic to realize that the "content creator" economy we live in today was built on the quiet legacy of what many would consider to be a happy accident.